Such antennas are known, for example, from U.S. Pat. No. 5,572,228, which is incorporated by reference, wherein they are realized in a mechanically pivoting manner by letting a surface-structured drum rotate in close proximity to a dielectric waveguide. The surface structuring of the drum is realized by individual metal strips, the distance of which varies when the drum rotates within the region of the dielectric waveguide. This effects power to be coupled out of the dielectric waveguide via a so-called leaky wave as a function of the rotational angle. The coupled-out power spreads in space in the form of radiation which can be described by a directional antenna pattern. The polarization of the radiated wave is oriented parallel to the metal strips present on the drum.
According to WO 2006/039 896 A1, which is incorporated by reference, an alternative waveguide type is used which is arranged in the vicinity of an interference structure such as a surface-structured drum. The waveguide comprises metallic sections spaced apart from one another and having a dielectric medium arranged in between them. The electromagnetic wave is coupled in between the metallic sections in the longitudinal direction. The metallic sections extend in the longitudinal direction, are open toward the interference structure and the side opposite to it in a first transverse direction and spaced apart from one another in a second transverse direction, wherein the second transverse direction is perpendicular to both the first transverse direction and the longitudinal direction of the waveguide. Such a waveguide exhibits high ohmic losses. An increased number of components leads to an increase in manufacturing costs and, due to the rotating cylinder, results in an antenna application which is prone to disturbances. Furthermore, the rotating cylinder requires the production tolerances and mechanical stresses to be reduced, such that the production expenditure increases even more, making such a waveguide cost-intensive.